So far more than fifty compounds have been synthesised or exfoliated as single layers (see Figure REF ). These include the well known monoelemental crystals (Xenes, e.g. graphene, phosphorene)[1]} and their ligand functionalised derivatives (Xanes, e.g. CF, GeH)[2]}, transition metal dichalcogenides (TMDCs, e.g. MoS\(_2\) , TaSe\(_2\) )[3]}, transition metal carbides and -nitrides (MXenes, e.g. Ti\(_2\) CO\(_2\) )[4]}, group III-V semiconductors and insulators (e.g. GaN, BN)[5]}, [6]}, transition metal halides (e.g. CrI\(_3\) )[7]}, [8]}, post-transition metal chalcogenides (e.g. GaS and GaSe)[9]}, [10]} and organic-inorganic hybrid perovskites (e.g. Pb(C\(_4\) H\(_9\) NH\(_3\) )\(_2\) I\(_4\) )[11]}. However, the already known monolayers are only the tip of a much larger iceberg. Indeed, recent data mining studies indicate that several hundred 2D materials could be exfoliated from known layered bulk crystals[12]}, [13]}, [14]}, [15]}. In the present work we take a complementary approach to 2D materials discovery based on combinatorial lattice decoration and identify another few hundred previously unknown and potentially synthesisable monolayers.
